<template>
  <div>
      <router-link tag="div" to="/" class="header-abs" v-show="showAbs"><div class="iconfont header-abs-back">&#xe624;</div></router-link>
      <div class="header-fixed" v-show="!showAbs" :style="opacityStyle">
          <router-link to="/">
             <div class="iconfont header-fixed-back">&#xe624;</div>
          </router-link>
          景点详情
      </div>
  </div>
</template>

<script>
export default {
  name: 'DetailHeader',
  data() {
    return {
      showAbs: true,
      opacityStyle: {opacity: 0}
    }
  },
  mounted() {
    //绑定到window上了
    window.addEventListener('scroll', this.handleScroll)
  },
  //   activdeated() {
  //     window.removeEventListener('scroll', this.handleScroll)
  // window.addEventListener('scroll', this.handleScroll)
  //   },

  beforeRouteLeave(to, from, next) {
    window.removeEventListener('scroll', this.handleScroll)
    next()
  },
  methods: {
    handleScroll(e) {
      const top = document.documentElement.scrollTop
      if (top > 60) {
        let opacity = top / 140
        opacity = opacity > 1 ? 1 : opacity
        console.log(opacity)

        this.opacityStyle = {
          opacity
        }
        this.showAbs = false
      } else {
        this.showAbs = true
      }
      console.log(document.documentElement.scrollTop)
    }
  }
}
</script>

<style lang="stylus" scoped>
@import '~style/varibles.styl';
    .header-abs{
        position:absolute;
        top:.2rem;
        left:.2rem;
        height:.8rem;
        line-height .8rem;
        width 0.8rem;
        text-align:center;
        border-radius:.4rem;
        background:rgba(0,0,0,.8);
        .header-abs-back{
            color:#fff
            font-size:.4rem;
        }
    }
    .header-fixed
        position:fixed
        top:0
        left:0;
        // width 100%
        right:0;
        // bottom:0;
        height $headerHeight
        line-height :$headerHeight
        text-align:center
        color:#fff;
        background:$bgColor
        font-size:.32rem
        z-index:99
    .header-fixed-back
        position:absolute
        top:0
        width:.64rem
        font-size:.4rem
        text-align :center
        color:#fff
</style>
